Michael Gunner will take on a new role with Australian billionaire Andrew "Twiggy" Forrest's renewable energy company, six months after resigning as the Northern Territory's chief minister.

Fortescue Future Industries (FFI) said Mr Gunner would act as the head of a new arm of the company in Northern Australia.

Mr Gunner served as chief minister for six years before making a shock resignation in May, following the birth of his second child.

Despite announcing the new job today, Mr Gunner will not start work until next month due to the NT's ministerial code of conduct, which prohibits former ministers from taking up work within six months of leaving office if that work relates to any of their former ministerial portfolios.

The time frame for restrictions on former ministers in the NT is much shorter than similar restrictions placed on federal ministers, who are prohibited from lobbying, advocating or meeting with government members for 18 months after leaving office.

From family time to renewable energy role

At the time of his resignation, Mr Gunner said he was stepping down to spend more time with his family and insisted he had not lined up any future work.

"My head and my heart are no longer here, they are at home," Mr Gunner said in May.

According to FFI, Mr Gunner's new role will see him establish a new office in Darwin, leading a team of staff exploring "job creating project opportunities" in the NT and northern Western Australia.

In a statement posted on his Facebook page, Mr Gunner said the job would allow him to "make a meaningful contribution to the world".

"I always knew I would have to go back to work – I also am guilty of enjoying work – but I need that work-life balance to be better than it was," he said.

Dr Forrest said Mr Gunner's experience working in northern Australia would make him a "valuable asset" for the company as it pushes to expand.

"We see enormous potential in the Northern Territory, with abundant wind and solar energy, and a community enthusiastic to embrace renewable energy and the employment intensive industries that come with it," the Fortescue chairman said.

Environment group slams 'devastating' legacy

During his tenure as chief minister, Mr Gunner controversially lifted a moratorium on fracking in the Northern Territory, subject to recommendations made as part of a scientific inquiry, including that the NT and federal governments seek to ensure no net increase in greenhouse gas emissions.